To determine the presence of anion and cation in the given salt
| Experiment | Observation | Inference |
|---|---|---|
| Take 0.1 g of salt in a test tube and add conc. H₂SO₄ | Deep violet vapour with a pungent odour is evolved | I⁻ may be present |
| Confirmatory Tests | ||
| Layer Test Take test solution or extract, add CHCl₃/CCl₄ and chlorine water dropwise, then shake vigorously | Violet colouration appears in the organic layer | I⁻ is confirmed |
| Silver Nitrate Test Acidify sodium carbonate extract with dilute HNO₃ and add AgNO₃ | Yellow precipitate is obtained, insoluble in excess NH₄OH | I⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Take 0.1 g of salt and add 1–2 mL of NaOH solution, then heat | A smell of ammonia is evolved | NH₄⁺ may be present |
| Bring a glass rod dipped in hydrochloric acid near the mouth of the test tube | Dense white fumes are observed | NH₄⁺ may be present |
| Confirmatory Test | ||
| Nessler's Reagent Test Pass the evolved gas through Nessler’s reagent | Brown colouration or a brown precipitate of basic mercury(II) amido-iodide is obtained | Presence of NH₄⁺ is confirmed |
The given salt contains NH₄⁺ ions as cation and I⁻ ions as anion. The salt is NH₄I.